针对在水中添加表面活性剂可以出现阻力系数减少而同时传热性能发生变化的现象,采用测压差装置和热电偶测温系统分别对二维流道内不同的减阻流体的减阻性能、传热性能进行了试验,研究了浓度、配比、雷诺数和热流密度对减阻流体传热与阻力系数之比值的影响。结果表明,表面活性剂减阻流体的传热系数考尔朋(Colburn)因子与阻力系数之比和水的情况有较大的差异;当减阻流体的减阻率稳定时,随着雷诺数的增大,考尔朋恩因子与阻力系数比值缓慢下降;达到临界雷诺数后,考尔朋因子与阻力系数之比值波动较大,并且比值迅速增大到接近没有添加减阻剂的水平。
The friction coefficient can be reduced by adding some Cetyltrimethyl Ammonium Chloride(CTAC) surfactant to water flow. The effect of concentration, mixture ratio, Reynolds number and heat flux of CTAC surfactant drag-reducing fluid has been investigated in a two-dimensional channel by using pressure difference transducer and temperature measuring system. The ratio of Colburn factor to friction coefficient has been experimentally investigated. The results indicate that this ratio is significantly different between it in the CTAC and that in water, especially at high drag reduction ratio. At steady drag reduction ratio, the ratio of Colburn factor to friction coefficient of drag-reducing fluid decreases steadily as Reynolds number is increasing when Reynolds number is below the critical value, however the ratio increases and fluctuates when Reynolds number is larger than the critical value.